The proposed research will evaluate the effectiveness of a comprehensive health promotion program for middle school students and their families based on a successful pilot study. Healthy for Life includes components addressing peer and family influences, the impact of the broader community, and the social service provider system. Thus, it moves beyond the classroom into the larger environment where students receive messages about their health behavior. Healthy for Life integrates several promising educational and prevention strategies from substance abuse prevention research into a unified, multidimensional program to prevent five causes of the new morbidity: poor nutrition, alcohol use, tobacco and marijuana use, and premature sexual activity. We will be comparing two versions of the program with the same content: an "intensive" program for 7th graders, and an "age-appropriate" version which spreads the program over 6th, 7th and 8th grades. The program is based on a social influences theory of adolescent health behavior. The research uses an experimental design in which 18 middle schools will be randomly assigned from matched triplets to one of two treatment conditions or a control condition. In the control schools students in a subsequent year will receive the program in a replication study. We estimate that 1800 seventh graders will be exposed to the program, and 600 students will be included in the control condition. Students will be surveyed annually over a four year period, assessing their knowledge, attitudes and behavior in the health risk areas of concern. Validation of self reports of smoking will be accomplished by measuring CO levels. Analysis will compare the long-term effectiveness of the program to the control condition, will compare the "age-appropriate" version to the "intensive" form, and also will address the theoretical derivation of the program model. A process evaluation will be used to asses and describe program implementation, identify unanticipated outcomes and confounding historical events. Healthy for Life is based on the research staff's experience in two years of piloting an in-school-only predecessor to the more refined, current model. The project has the potential to demonstrate the efficacy of an innovative approach to adolescent health promotion generally, and alcohol and drug abuse specifically, with implications for community, family and school programs.